[KuroCX30]

Several new additions and corrections to the chart which will now be located on the first post:

Plus Size Tires

Reference Chart: General Tire Size Options: Keep in mind that these are general size groups that I have curated that should be considered for tire sizing. Exact measurements of a tire vary within each size group depending on the tire type, brand and model. Always check the exact measurements...

www.cx30talk.com

 

[dwmilton]

Wow. Kudos to the OP for this thread!

I’ve just finished reading through, as I plan to upgrade my wife’s ‘21 CX-30 Turbo, once the OE tires have worn some more. She loves her little scooter, but wishes it had better steering response and grip, for more confidence cornering. I know she also values ride comfort, so I don’t plan to plus-size.

My current mindset is 235/50-18 Conti DWSs on 18x8 wheels; most likely an Enkei of some sort, as we’ve had good luck with those brands in the past. Definitely a MAT or flow-formed wheel, for weight savings. We had 18x8 TM7s (storm gray) on her 2018 Mazda 3 Touring, that was traded for the ‘30. She really liked the style of those, so maybe the same, but in black for her new scooter.

Thoughts and input are greatly welcomed!

 

[KuroCX30]

Wow. Kudos to the OP for this thread!

I’ve just finished reading through, as I plan to upgrade my wife’s ‘21 CX-30 Turbo, once the OE tires have worn some more. She loves her little scooter, but wishes it had better steering response and grip, for more confidence cornering. I know she also values ride comfort, so I don’t plan to plus-size.

My current mindset is 235/50-18 Conti DWSs on 18x8 wheels; most likely an Enkei of some sort, as we’ve had good luck with those brands in the past. Definitely a MAT or flow-formed wheel, for weight savings. We had 18x8 TM7s (storm gray) on her 2018 Mazda 3 Touring, that was traded for the ‘30. She really liked the style of those, so maybe the same, but in black for her new scooter.

Thoughts and input are greatly welcomed!

Thanks @dwmilton !

I ran some calculations for a 18x8 wheel. It looks like a +37 to +42 would put you closest to flush front wheel fitment. If you want to maximize steering response and grip, I would bump the size up to 245/50r18, which gives you 0.7" more tread width without rubbing. A 235/50 will of course fit fine as well. I like Enkei, they are the most affordable real wheel available. I'm not a fan of the directional spoke of the TM7 as it limits tire rotation. A similar style spoke model is the Enkei Raijin, which comes in 18x8 +40. These will be right around 20-21 lb each.

 

[dwmilton]

Thanks @dwmilton !

I ran some calculations for a 18x8 wheel. It looks like a +37 to +42 would put you closest to flush front wheel fitment. If you want to maximize steering response and grip, I would bump the size up to 245/50r18, which gives you 0.7" more tread width without rubbing. A 235/50 will of course fit fine as well. I like Enkei, they are the most affordable real wheel available. I'm not a fan of the directional spoke of the TM7 as it limits tire rotation. A similar style spoke model is the Enkei Raijin, which comes in 18x8 +40. These will be right around 20-21 lb each.

Thank you, for the info. I know what you mean, regarding the directional spokes, LOL. She liked being different, and it's definitely not a wheel style we see around here.

I looked on Tire Rack, but they only recommend 40mm (or less) offset wheels for the CX-30, so the TM7 isn't listed. I asked the online chat guru, and he stated that their engineers felt 45 would be too much offset for an 8" wide wheel on the CX-30; and that it had different fitment requirements than our 2018 Mazda 3 Touring did.

In your educated opinion, should we avoid an 8" 45mm offset wheel for our CX-30? If I have to exclude the TM7, I'll grudgingly shop 40mm offset wheels, just want to be safe. I plan to wrap whatever wheels we get in DWS-06+ rubber, if this affects the wheel recommendation.

Thanks Again!

 

[KuroCX30]

I looked on Tire Rack, but they only recommend 40mm (or less) offset wheels for the CX-30, so the TM7 isn't listed. I asked the online chat guru, and he stated that their engineers felt 45 would be too much offset for an 8" wide wheel on the CX-30; and that it had different fitment requirements than our 2018 Mazda 3 Touring did.

In your educated opinion, should we avoid an 8" 45mm offset wheel for our CX-30? If I have to exclude the TM7, I'll grudgingly shop 40mm offset wheels, just want to be safe. I plan to wrap whatever wheels we get in DWS-06+ rubber, if this affects the wheel recommendation.

Thanks Again!

The engineers are being conservative. A 45 offset is the OEM offset and will work up to an 8.5" wide wheel with the appropriate tire size. However, a 45 offset for an 8" wheel will rub on the rear suspension with a 245/50 DWS-06+, you would need to lower the offset if you wanted to go with a 245 OR go with a 235/50 DWS-06+ like you originally stated. So, a TM-7 18x8 +45 with a 235/50 DWS-06+ gets an easy green light.

 

[dwmilton]

Excellent! Thanks very much; opens up my shopping some!

The engineers are being conservative. A 45 offset is the OEM offset and will work up to an 8.5" wide wheel with the appropriate tire size. However, a 45 offset for an 8" wheel will rub on the rear suspension with a 245/50 DWS-06+, you would need to lower the offset if you wanted to go with a 245 OR go with a 235/50 DWS-06+ like you originally stated. So, a TM-7 18x8 +45 with a 235/50 DWS-06+ gets an easy green light.

 

[22Turbo]

One thing to note is that tire sizes vary between brands. I had read it before but thought it was minimal. While looking at 245/50/18 specs I noticed the Continental DWS 06 Plus is 27.65 inches. While the Michelin Pilot Sport A/S 4 is 28.1 inches. These are per the Discount Tire website. That is a huge difference when things are tight.

 

[dwmilton]

Definitely good to know. I plan to stick with 235/50, and I’m a huge fan of the Conti’s, so all is well. Having said all that, I may still opt for a 18x8 with 40mm offset, just for extra breathing room and flushness.

Really appreciate the great info from you guys!

One thing to note is that tire sizes vary between brands. I had read it before but thought it was minimal. While looking at 245/50/18 specs I noticed the Continental DWS 06 Plus is 27.65 inches. While the Michelin Pilot Sport A/S 4 is 28.1 inches. These are per the Discount Tire website. That is a huge difference when things are tight.

 

[KuroCX30]

One thing to note is that tire sizes vary between brands. I had read it before but thought it was minimal. While looking at 245/50/18 specs I noticed the Continental DWS 06 Plus is 27.65 inches. While the Michelin Pilot Sport A/S 4 is 28.1 inches. These are per the Discount Tire website. That is a huge difference when things are tight.

All of my calculations always take into account the specific tire brand, model and size in question.

 

[22Turbo]

All of my calculations always take into account the specific tire brand, model and size in question.

Thanks for all the work you do. Not sure if you might know but trying to figure out if the no rubbing means at full lock? Only curious because I am at a point of frustration because I have the 2nd shortest tires and only have 235s and the outer part of the tires are only about 1/4 to 1/2 inch from rubbing on the front inner fender liner at full lock. Back isn't as tight but still only about 5/8 to 3/4 inch of clearance. At 35mm offset and 8.5 width, I have the same width and/or offset as several members that run heights almost an inch taller and 10mm wider. It doesn't even look like one size bigger or even a tall 235/50 would fit. Any ideas? Just trying to keep it within 1% less than OEM height or taller and run either a 245 or 255 width.

 

[KuroCX30]

Didn't realize that. Just wanted to throw it out there because if people are only looking at the size and thinking

It's worth mentioning from time to time as assuming all sizes of brands/models are the same is a common mistake people make.

Thanks for all the work you do. Not sure if you might know but trying to figure out if the no rubbing means at full lock? Only curious because I am at a point of frustration because I have the 2nd shortest tires and only have 235s and the outer part of the tires are only about 1/4 to 1/2 inch from rubbing on the front inner fender liner at full lock. Back isn't as tight but still only about 5/8 to 3/4 inch of clearance. At 35mm offset and 8.5 width, I have the same width and/or offset as several members that run heights almost an inch taller and 10mm wider. It doesn't even look like one size bigger or even a tall 235/50 would fit. Any ideas? Just trying to keep it within 1% less than OEM height or taller and run either a 245 or 255 width.

You're welcome. No rubbing means at full turn lock against the plastic liner of the wheel well and/or against the suspension components. The latter should not be an issue for you with a 35 offset. 1/4" to 1/2" may not seem like much but it is a significant amount of clearance. I ran the numbers for a couple of examples so let's go ahead and compare with what you are currently rolling on:

Size - Model - Diameter - OEM Difference - Tread Width - Hypotenuse
235/50 - P Zero Nero - 27.3" --------- 0% - 8.0" - 28.35" (current)
245/50 - P Zero AS ---- 27.7" - (+1.45%) - 8.1" - 28.86" (will clear)
255/45 - P Zero AS ---- 27.0" - (-1.14%) - 8.5" - 28.31" (will clear)
265/45 - M. PS4 AS -- 27.4" - (+0.36%) - 8.5" - 28.69" (will clear, maximum manufacturer's recommended size for 8.5" wide wheel)

I didn't include the adjusted section width as you have already given yourself a 10 mm cushion with your 35 mm offset so the suspension is clear both in the rear and front on the above examples. The calculation that we are concerned with when determining the wheel well rub at full turn lock is the hypotenuse of the tire... measuring the point of the inner tread width edge to the opposite tread width edge on the opposite end of the tire. This will give us the maximum length the tire can "reach" when turning, ie. the contact points to the wheel well plastic. Here is a crude diagram of what I'm describing:

From what I've read, matching (or plus ½") the wheel width to the tread width provides the best handling in dry conditions with all other tire variables the same (type, brand, model). The 265/45 Michelin Pilot Sport 4 All Season is the widest tire you can go with regards to staying within your diameter requirements and within the manufacturer's recommendation wheel width. It also gives you the optimal tread width. Hope that helps.

 

[22Turbo]

I'll just go for it then and have the installer check just to make sure on the 1st one. Just want to get the Pirelli's off since one on the back is out of round and had to plug another. Attached a few pics for reference.

 

[KuroCX30]

I'll just go for it then and have the installer check just to make sure on the 1st one. Just want to get the Pirelli's off since one on the back is out of round and had to plug another. Attached take a few pics for reference.

Which tire are you going for?

 

[22Turbo]

Which tire are you going for?

I felt dumb after sweating over all the tiny stuff that I forgot to only half the increase in size effects rubbing

Ended up ordering the DWS06 Plus in 255/45/18 since it's lighter than the Michelin. Not sure by how much because Discount and Tirerack list different weights than the Michelin and Continental websites.

Also decided to lower with coilovers in the near future so I decided against trying to go bigger in diameter to help fill the wheel well gaps.

.

 

[KuroCX30]

I felt dumb after sweating over all the tiny stuff that I forgot to only half the increase in size effects rubbing

Ended up ordering the DWS06 Plus in 255/45/18 since it's lighter than the Michelin. Not sure by how much because Discount and Tirerack list different weights than the Michelin and Continental websites.

Also decided to lower with coilovers in the near future so I decided against trying to go bigger in diameter to help fill the wheel well gaps.

Nice, the DWS06 Plus is highly regarded. Your new setup will come in about 5 lb lighter than than OEM and the new tire hypotenuse will be 1 mm less than the P Zero Nero obviously making it an easy fit. Do share some photos after the install and good luck with the coilovers.

 

[30pilot]

S

It's worth mentioning from time to time as assuming all sizes of brands/models are the same is a common mistake people make.



You're welcome. No rubbing means at full turn lock against the plastic liner of the wheel well and/or against the suspension components. The latter should not be an issue for you with a 35 offset. 1/4" to 1/2" may not seem like much but it is a significant amount of clearance. I ran the numbers for a couple of examples so let's go ahead and compare with what you are currently rolling on:

Size - Model - Diameter - OEM Difference - Tread Width - Hypotenuse
235/50 - P Zero Nero - 27.3" --------- 0% - 8.0" - 28.35" (current)
245/50 - P Zero AS ---- 27.7" - (+1.45%) - 8.1" - 28.86" (will clear)
255/45 - P Zero AS ---- 27.0" - (-1.14%) - 8.5" - 28.31" (will clear)
265/45 - M. PS4 AS -- 27.4" - (+0.36%) - 8.5" - 28.69" (will clear, maximum manufacturer's recommended size for 8.5" wide wheel)

I didn't include the adjusted section width as you have already given yourself a 10 mm cushion with your 35 mm offset so the suspension is clear both in the rear and front on the above examples. The calculation that we are concerned with when determining the wheel well rub at full turn lock is the hypotenuse of the tire... measuring the point of the inner tread width edge to the opposite tread width edge on the opposite end of the tire. This will give us the maximum length the tire can "reach" when turning, ie. the contact points to the wheel well plastic. Here is a crude diagram of what I'm describing:
View attachment 6694


From what I've read, matching (or plus ½") the wheel width to the tread width provides the best handling in dry conditions with all other tire variables the same (type, brand, model). The 265/45 Michelin Pilot Sport 4 All Season is the widest tire you can go with regards to staying within your diameter requirements and within the manufacturer's recommendation wheel width. It also gives you the optimal tread width. Hope that helps.

Saving this reply, when I need tires I will contact you. Not being an expert does not mean that I have to put up with something less than best, ...so I will contact the experts. When you think about it, your vehicle response to throttle and steering inputs can only be transferred to the road by the tires. It pays to get the best for your kind of vehicle and your use of it.
PS: My wife of 50 years has a response to every question. However it doesn't hurt to get a second opinion.

 

[dwmilton]

All of this wheel and tire porn has me considering wider combinations. I’ll include 18x8.5 wheels, and 255-265/45 tires in the search. I’ve wanted to avoid going taller, as her car seems to have plenty of sidewall, but I can be open-minded here.

Will see what sizes the DWS+ comes in. Thanks again guys!…you’re spreading the disease.

 

[Trickster]

Well a 255/45/18 = 4.5”
A 265/45/18 = 4.7”
I wouldn’t call those “plenty” of sidewall.

 

[dwmilton]

Well a 255/45/18 = 4.5”
A 265/45/18 = 4.7”
I wouldn’t call those “plenty” of sidewall.

Coming from her previous Mazda 3 with 225/45, and our F Type with 245/40 (front)…these give a little more protection, LOL!

 

[KuroCX30]

All of this wheel and tire porn has me considering wider combinations. I’ll include 18x8.5 wheels, and 255-265/45 tires in the search. I’ve wanted to avoid going taller, as her car seems to have plenty of sidewall, but I can be open-minded here.

Will see what sizes the DWS+ comes in. Thanks again guys!…you’re spreading the disease.

I'm a big fan of larger diameter tires on the CX-30. It helps fill the enormous gap and every little bit of gap reduction is a visual improvement. I also like a little more ground clearance and being up just a bit higher when driving.

The best option for maximizing diameter without rubbing with the DWS 06+ would be the 235/55 at 28.2". This would be a good fit on an 18x8.5 +45.

If you don't mind a little rub and/or heating up the wheel well plastic with a heat gun to reform it just a tad, you could go with the 245/55 at 28.6". If you wanted this tire on an 18x8.5, I'd suggest a +38 to +40 offset for that wheel. Any higher and you're running into issues with the tire rubbing the suspension in the rear. +38 would be the safest bet.